def task1(sample_size, dimension_size):
X, y = datasets.make_sparse_uncorrelated(sample_size, dimension_size)
X_train, X_test, y_train, y_test = model_selection.train_test_split(
X, y, test_size=0.3, train_size=0.7)
reg = linear_model.SGDRegressor(max_iter=1000)
reg.fit(X_train, y_train)
y_predict = reg.predict(X_test)
error = metrics.mean_squared_error(y_test, y_predict)
return error
time_list = list()
error_list = list()
for r in [100, 1000, 2000]:
for i in range(0, 5):
start = time.time()
error_list.append(task1(10000, r))
stop = time.time()
time_list.append(stop - start)
print(
str(r) + ": Error:" + str(sum(error_list) / len(error_list)) +
"-time:" + str(sum(time_list)))
for r in [100000, 250000, 500000]:
for i in range(0, 5):
start = time.time()
error_list.append(task1(10000, r))
stop = time.time()
time_list.append(stop - start)
print(
str(r) + ": Error:" + str(sum(error_list) / len(error_list)) +
"-time:" + str(sum(time_list)))
def generators_for_regression_datasets(self):
"""
Generators for regression
sparse random linear combination of random features, with noise
make_sparse_uncorrelated
"""
logging.debug('----------------- Generators for regression -----------')
print('sparse_uncorrelated ' , datasets.make_sparse_uncorrelated())
def test_linear_regression_positive_vs_nonpositive():
# Test differences with LinearRegression when positive=False.
X, y = make_sparse_uncorrelated(random_state=0)
reg = LinearRegression(positive=True)
reg.fit(X, y)
regn = LinearRegression(positive=False)
regn.fit(X, y)
assert np.mean((reg.coef_ - regn.coef_)**2) > 1e-3
def get_data(dataset_name):
print("Getting dataset: %s" % dataset_name)
if dataset_name == "lfw_people":
X = fetch_lfw_people().data
elif dataset_name == "20newsgroups":
X = fetch_20newsgroups_vectorized().data[:, :100000]
elif dataset_name == "olivetti_faces":
X = fetch_olivetti_faces().data
elif dataset_name == "rcv1":
X = fetch_rcv1().data
elif dataset_name == "CIFAR":
if handle_missing_dataset(CIFAR_FOLDER) == "skip":
return
X1 = [
unpickle("%sdata_batch_%d" % (CIFAR_FOLDER, i + 1))
for i in range(5)
]
X = np.vstack(X1)
del X1
elif dataset_name == "SVHN":
if handle_missing_dataset(SVHN_FOLDER) == 0:
return
X1 = sp.io.loadmat("%strain_32x32.mat" % SVHN_FOLDER)["X"]
X2 = [X1[:, :, :, i].reshape(32 * 32 * 3) for i in range(X1.shape[3])]
X = np.vstack(X2)
del X1
del X2
elif dataset_name == "low rank matrix":
X = make_low_rank_matrix(
n_samples=500,
n_features=int(1e4),
effective_rank=100,
tail_strength=0.5,
random_state=random_state,
)
elif dataset_name == "uncorrelated matrix":
X, _ = make_sparse_uncorrelated(n_samples=500,
n_features=10000,
random_state=random_state)
elif dataset_name == "big sparse matrix":
sparsity = int(1e6)
size = int(1e6)
small_size = int(1e4)
data = np.random.normal(0, 1, int(sparsity / 10))
data = np.repeat(data, 10)
row = np.random.uniform(0, small_size, sparsity)
col = np.random.uniform(0, small_size, sparsity)
X = sp.sparse.csr_matrix((data, (row, col)), shape=(size, small_size))
del data
del row
del col
else:
X = fetch_openml(dataset_name, parser="auto").data
return X
def task2_sampling(sample_size, dimension_size, new_sample_size):
X, y = datasets.make_sparse_uncorrelated(sample_size, dimension_size)
X_new, y_new = resample(X, y, n_samples=new_sample_size, replace=False)
X_train, X_test, y_train, y_test = model_selection.train_test_split(
X_new, y_new, test_size=0.3, train_size=0.7)
start = time.time()
reg = linear_model.SGDRegressor(max_iter=1000)
reg.fit(X_train, y_train)
y_predict = reg.predict(X_test)
error = metrics.mean_squared_error(y_test, y_predict)
stop = time.time()
return error, stop - start
def task2_pca(sample_size, dimension_size, component_size):
X, y = datasets.make_sparse_uncorrelated(sample_size, dimension_size)
pca = decomposition.PCA(n_components=component_size)
pca.fit(X)
new_X = pca.transform(X)
X_train, X_test, y_train, y_test = model_selection.train_test_split(
new_X, y, test_size=0.3, train_size=0.7)
start = time.time()
reg = linear_model.SGDRegressor(max_iter=1000)
reg.fit(X_train, y_train)
y_predict = reg.predict(X_test)
error = metrics.mean_squared_error(y_test, y_predict)
stop = time.time()
return error, stop - start
def test_linear_regression_positive_multiple_outcome(random_state=0):
# Test multiple-outcome nonnegative linear regressions
random_state = check_random_state(random_state)
X, y = make_sparse_uncorrelated(random_state=random_state)
Y = np.vstack((y, y)).T
n_features = X.shape[1]
ols = LinearRegression(positive=True)
ols.fit(X, Y)
assert ols.coef_.shape == (2, n_features)
assert np.all(ols.coef_ >= 0.0)
Y_pred = ols.predict(X)
ols.fit(X, y.ravel())
y_pred = ols.predict(X)
assert_allclose(np.vstack((y_pred, y_pred)).T, Y_pred)
def test_linear_regression_sparse_multiple_outcome(random_state=0):
# Test multiple-outcome linear regressions with sparse data
random_state = check_random_state(random_state)
X, y = make_sparse_uncorrelated(random_state=random_state)
X = sparse.coo_matrix(X)
Y = np.vstack((y, y)).T
n_features = X.shape[1]
ols = LinearRegression()
ols.fit(X, Y)
assert ols.coef_.shape == (2, n_features)
Y_pred = ols.predict(X)
ols.fit(X, y.ravel())
y_pred = ols.predict(X)
assert_array_almost_equal(np.vstack((y_pred, y_pred)).T, Y_pred, decimal=3)
def test_linear_regression_sparse_multiple_outcome(setup, random_state=0):
# Test multiple-outcome linear regressions with sparse data
random_state = check_random_state(random_state)
X, y = make_sparse_uncorrelated(random_state=random_state)
X = sparse.coo_matrix(X)
Y = np.vstack((y, y)).T
ols = LinearRegression()
error_msg = re.escape("Does not support sparse input!")
with pytest.raises(NotImplementedError, match=error_msg):
ols.fit(X, Y)
error_msg = re.escape("Does not support sparse input!")
with pytest.raises(NotImplementedError, match=error_msg):
ols.fit(X, y.ravel())
def test_residualize_linear():
"""sanity checks on implementation"""
min_dim = 6 # atleast 4+ required for make_sparse_uncorrelated
max_dim = 100
for n_samples in np.random.randint(20, 500, 3):
for num_confounds in np.random.randint(min_dim, max_dim, 3):
train_all, train_y = make_sparse_uncorrelated(
n_samples=n_samples, n_features=min_dim + num_confounds + 1)
train_X, train_confounds = splitter_X_confounds(train_all, num_confounds)
resid = Residualize(model='linear')
resid.fit(train_X, train_confounds)
residual_train_X = resid.transform(train_X, train_confounds)
# residual_train_X and train_confounds must be orthogonal now!
assert_almost_equal(residual_train_X.T.dot(train_confounds), 0)
def test_make_sparse_uncorrelated():
X, y = make_sparse_uncorrelated(n_samples=5, n_features=10, random_state=0)
assert_equal(X.shape, (5, 10), "X shape mismatch")
assert_equal(y.shape, (5,), "y shape mismatch")
def test_make_sparse_uncorrelated():
X, y = make_sparse_uncorrelated(n_samples=5, n_features=10, random_state=0)
assert X.shape == (5, 10), "X shape mismatch"
assert y.shape == (5, ), "y shape mismatch"
from sklearn import datasets
import matplotlib.pyplot as plt
# make_sparse_uncorrelated data
X,y = datasets.make_sparse_uncorrelated(
n_samples=100,n_features=10,random_state=None)
print('X = ')
print(X)
print('y = ')
print(y)
print("the output of make_hastie_10_2() :: ", datasets.make_hastie_10_2())
#make_moons() executed
print("the output of make_moons() :: ", datasets.make_moons())
#make_multilabel_classification() executed
print("the output of make_multilabel_classification() :: ",
datasets.make_multilabel_classification())
#make_regression() executed
print("the output of make_regression() :: ", datasets.make_regression())
#make_sparse_spd_matrix() executed
print("the output of make_sparse_spd_matrix() :: ",
datasets.make_sparse_spd_matrix())
#make_sparse_uncorrelated() executed
print("the output of make_sparse_uncorrelated() :: ",
datasets.make_sparse_uncorrelated())
#make_sparse_uncorrelated() executed
print("the output of make_sparse_uncorrelated() :: ",
datasets.make_sparse_uncorrelated())
#make_swiss_roll() executed
print("the output of make_swiss_roll() :: ", datasets.make_swiss_roll())
#mldata_filename() executed
print("the output of mldata_filename() :: ",
datasets.mldata_filename('iris.txt'))
random_state = 414
saving_fig = False # set to True to save images
# dataset = "synthetic_unco" # Fig a
dataset = "synthetic" # Fig b
if dataset is "synthetic":
n_samples, n_features = (500, 5000)
X, y = make_regression(n_samples=n_samples,
n_features=n_features,
random_state=random_state)
if dataset is "synthetic_unco":
n_samples, n_features = (30, 50)
X, y = make_sparse_uncorrelated(n_samples=n_samples,
n_features=n_features,
random_state=random_state)
X = X.astype(float)
y = y.astype(float)
X = np.asfortranarray(X)
y = np.asfortranarray(y)
n_samples, n_features = X.shape
X = np.asfortranarray(X)
y = np.asfortranarray(y)
X /= np.linalg.norm(X, axis=0)
y = (y - y.mean()) / y.std()
X_train, X_test, y_train, y_test =\
train_test_split(X, y, test_size=0.30, random_state=random_state)
# -*- encoding: utf-8 -*-
"""
8.5.1 线性回归
"""
from sklearn.datasets import make_sparse_uncorrelated
from sklearn.linear_model import LinearRegression, Ridge
from sklearn.model_selection import train_test_split as tsplit
from sklearn import metrics
import matplotlib.pyplot as plt
import numpy as np
X, y = make_sparse_uncorrelated(n_samples=100, n_features=4)
X_train, X_test, y_train, y_test = tsplit(X, y, test_size=0.1)
reg = LinearRegression() # 实例化最小二乘法线性回归模型
reg.fit(X_train, y_train) # 训练
y_pred = reg.predict(X_test) # 预测
print(y_pred) # 预测结果
print(y_test) # 实际结果
print(metrics.mean_squared_error(y_test, y_pred)) # 均方误差
print(metrics.r2_score(y_test, y_pred)) # 复相关系数
print(metrics.median_absolute_error(y_test, y_pred)) # 中位数绝对误差
plt.rcParams['font.sans-serif'] = ['FangSong']
plt.rcParams['axes.unicode_minus'] = False
plt.subplot(121)
plt.title('残差图')
plt.plot(y_pred - y_test, 'o')
